The field of this invention is well screens.
In the prior art, it has been customary to secure a wire screen sleeve on a perforated pipe with end retainer rings at each end of the sleeve. Such end retainer rings have an external diameter which is greater than the external diameter of the wire screen sleeve, thus requiring a larger bore size for such end rings to pass therethrough than would be required for the sleeve diameter itself. The prior art construction using such end rings has resulted in gaps between an end ring and the end of the external wire screen which has been sufficient to permit fluid cutting action by the well fluid flowing through such gaps. Further, such end rings do not prevent rotational movement of the sleeve relative to the pipe, and if a torque is applied to the pipe, the screen sleeve is subject to twisting out of one or both of the end rings, resulting in an exposure of an open end or ends of the screen sleeve. Also, when it becomes necessary to mill off the screen for a fishing job, after the upper end ring is milled off, it is often impossible to mill off the screen sleeve because it simply rotates with the milling tool. Stretching of the pipe is also apt to expose one or both ends of the screen sleeve since the end rings move with the pipe.